The major goal of the proposed research is to employ neuroimaging to characterize brain areas related to aspects of explicit memory and skill learning. This grant proposes 4 sets of experiments designed: 1. To characterize the relationship of specific brain regions to aspects of memory encoding. Experiments are proposed to test if there is a direct relationship of dorsal frontal and medial temporal cortex to explicit encoding, and if so, what types of information or task demands are related to specific areas (e.g., a specific relationship between left dorsal frontal cortex and the encoding of verbal information). 2. To test for reactivation of specific processing regions during memory retrieval. A commonly and strongly held belief in the neuroscience of memory is the idea that, during retrieval, neurons that processed specific information during encoding will be "reactivated" (e.g., neurons in auditory processing areas will be activated when a person tries to remember a voice). Experiments testing this idea, however, have met with mixed success. Experiments are proposed to provide a strong test of this claim. 3. To characterize the specific contributions of brain areas to the skill learning. Experiments are proposed to characterize more fully the relation of different regions to distinct types of information used in skill acquisition on a single task (design tracing). Other skill learning experiments explore the level of abstraction of programs used to perform different versions of this task, and the functional anatomy related to the information. 4. To examine the effects of explicit memory demands on the functional anatomy of skill learning tasks. A final series of experiments looks at the relation between the explicit and procedural memory by placing explicit demands on subjects performing a learning task. The purpose is to provide a better understanding of how explicit demands interact both beneficially and detrimentally with skill learning, and the functional anatomy associated with these effects. Second, these manipulations may provide useful information about how learning a particular skill may be implemented through parallel functional anatomical pathways. The main purpose of this grant is to develop a basic understanding of the neural mechanisms underlying learning and memory. However, one beneficial outcome of understanding the various subsystems is the ability to develop specific rehabilitation strategies based on a more complete understanding of the many parallel systems involved, and the interactions between them.